


Calculated

by abluevixen (knightofbows)



Series: | January 2016 Prompt Challenge | [17]
Category: Teen Wolf (TV)
Genre: Alternate Universe - Canon Divergence, Canon-Typical Violence, Established Derek Hale/Stiles Stilinski, M/M, Married Melissa McCall/Sheriff Stilinski, Mates Derek Hale/Stiles Stilinski, Scott and Stiles are Step-Brothers, alpha!Derek, alpha!Scott, sister!Julia Stilinski-Delgado
Language: English
Status: Completed
Published: 2016-03-06
Updated: 2016-03-06
Packaged: 2018-05-25 01:13:55
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 1,217
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6174370
Author URL: https://archiveofourown.org/users/knightofbows/pseuds/abluevixen
Summary: <blockquote class="userstuff">
              <p>Scott and Stiles need to save their sister. Derek doesn't like their plan.</p>
            </blockquote>





	Calculated

“It’s a risk,” Scott said. “A huge risk.”

A topographical map of the preserve, collected from the Hale vault, lay spread on the large metal examination table in the back of the Beacon Hills Veterinary Clinic. Penciled marks indicated where each of the first three victims had been found. The Mixcoatl Cult—some bastardized version of ancient Aztec worship—had taken up shop in Beacon Hills some few weeks prior, just before a slew of children went missing.

The most recent disappearance: Julia Stilinski-Delgado.

“Yeah,” Stiles grumbled. How he looked at Scott was clearly a warning. “A _calculated_ risk. I’ll be fine. Deaton’s already assured us their magic is flawed. The Nemeton isn’t responding to their practices. We can’t let them know that, though. We have to do this.”

“It’s not worth your life to let them think their twisted rituals are working,” Derek growled. He lingered in the corner of the examination room. He understood the importance of family. Stiles and Scott needed to lead the charge of finding their younger sister—Derek understood that need all too well.

“Derek,” Lydia warned, her voice gentle. She stood beside Stiles, filling the space of comfort and support Derek normally occupied. But Derek wasn’t what Stiles needed right then—Lydia, with her compassion and keen understanding, however, was.

Derek was too exhausted from their efforts of keeping the Sheriff and Melissa out of the ordeal to bother arguing, though it pained him that he couldn’t give Stiles what he needed.

“Well, Scott can’t do it!” Stiles shouted. “He’s not fit for sacrifice!”

“But you are?” Scott’s eyes flashed vicious crimson. “You aren’t a virgin, Stiles,” he sneered, and Derek suppressed a reflexive flinch. “You’re in your twenties.”

“I could say the same for you!” Stiles argued. “But you also aren’t human.”

“You aren’t a warrior,” Scott insisted.

Stiles’ eyes widened for only a moment before his face curled into a snarl. “Like hell I’m not! I’m one of the only fucking humans left in this goddamn town, it seems, and I’ve been running with the Pack from the fucking beginning. I _am_ a warrior, thank you very fucking much.” He leaned over the table as if prepared to launch himself at Scott. “I am the _perfect_ fucking sacrifice to their war god. I’m the brother of one alpha werewolf, and mated to another; I’ve spilled just as much blood as I’ve bled; and these assholes have my sister.”

“She’s my sister, too,” Scott murmured.

“Then help me save her,” Stiles hissed.

Derek scented Scott’s resignation before he nodded.

Stiles, however, didn’t smell pleased. Just sad.

 

###

 

“Calm your eyebrows, Sourwolf, or your face will be stuck that way,” Stiles muttered. He lead the way through the preserve, to the specifically chosen and triangulated tree that would be the place the cult brought Julia—the place where Stiles would be prepared, in advance, as a sacrifice, in her place. “Here it is,” he said.

“I hate when you call me that,” Derek answered, the words familiar on his tongue. He couldn’t really help how his fangs elongated in his mouth, or how his eyes burned with their familiar, powerful, scarlet flare. Every part of him—the man, the wolf, the lover, the mate—hated what he had to do. It bucked, heavy and violent, against his every instinct, his very nature. The rope slung over his shoulder only drove the point home.

“It’s nostalgic,” Stiles retorted.

Derek’s frown deepened. “It reminds me of how you hated me.”

Stiles sighed, and pulled a folded piece of notebook paper from his pocket. “I never hated you, Der,” he said. He took one of Derek’s hands, the wolf’s fingertips ending in razor points, and used his claw as a pen or paintbrush, easily carving runic markings into the bark of the tree. “I just didn’t know how to love you.”

Derek snorted, disbelieving despite his mate’s steady heartbeat.

“I didn’t know how you needed to be loved,” Stiles elaborated. “I don’t think you knew, either.” He smelled like grief, and Derek’s wolf whimpered in the back of his mind. “So, I never hated you.” Once he finished carving the ruins, he fit his fingers in the spaces between Derek’s. “I was intimidated—still am, sometimes—but never afraid. And I never hated you.”

“You might, after this.”

“I would never.”

“And if this doesn’t work?”

“It wouldn’t be your fault, Derek.”

“I can’t have someone else die because of me. I can’t hurt another person I love.”

Stiles stepped into Derek’s space, the toes of their shoes touching, and cupped the werewolf’s face with both of his warm, steady hands. “Neither of those things will happen, okay? I promise you. We _will_ save Julia, and I _will_ come out of this okay.”

“Scarred,” Derek murmured. “You’ll be scarred.”

“No more than I already am,” Stiles countered.

“By _my_ hand,” Derek hissed.

“Because _I trust you_ , Derek,” Stiles pushed, angry and urgent and smelling suddenly of crippling fear. “I love you, and I trust you, which is why I need you to do this and not Scott.”

When Derek whimpered, Stiles kissed him, hard and insistent, like he still had something to prove despite how long they’d been together. But Derek needed it too, and his arms wound around Stiles’ waist to hold him close, to savor his taste and his scent and the sensation of him so close and _Derek’s_.

“You’re asking me to _hurt you_.”

Stiles pulled away, brushing their noses together, and breathed, “Tie me up, Der.”

So Derek did, assuring Stiles could easily escape his knotted bindings if necessary.

“Now the markings.”

“Stiles…” Derek pleaded. But he was already committed. The tree was already marked. Stiles was already bound. All Derek needed to do was paint Stiles with the required symbols, carve them into his tender flesh until they welled crimson and angry with his human blood, his warrior’s blood.

“It’s for Julia,” Stiles insisted, his voice cracked at the edge. “It’s for my sister, Derek, please. You’d do it for Cora, and I’d do it for you. If I had to cut you up for Cora, and you wanted me to, I’d do it, Der. I’d do it in an instant. Listen to my heartbeat. You know it’s true.”

Derek surged forward. While his claws raked Stiles’ chest, tearing flesh and cloth alike, he swallowed Stiles’ yelp of pain with a kiss. He knew Stiles’ body as well as his own, knew just the pressure needed to draw just enough blood, and had practiced the shapes he’d draw into his mate’s body with blunt fingertips and a reverent touches after burning moonlight in their bed.

He worked quickly, deftly, for Stiles’ sake. After carving Stiles’ chest, then one arm, and then the other, he retracted his claws and painted the last sigils on Stiles’ cheeks and forehead.

Stiles, however, shivered when shock set in. Derek scented it rolling off of him in waves, the way his body couldn’t cope with the sudden trauma it endured, how it didn’t keep up with the heat and blood it lost. “Love you, Der,” Stiles murmured.

Derek kissed him again. “I love you, too. We’ll get your sister back. I promise.”

“I know,” Stiles said, his smirk weak, but still characteristic. “Thank you.”

**Author's Note:**

> Part 2: [Prompt 22: The Clouds Gather](http://archiveofourown.org/works/6216061)
> 
> You can also find me on tumblr: [foxtricks](http://foxtricks.tumblr.com/)


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